'Six pack' holders and discarded fishing gear - guilty of killing marine turtles according to new research

We have seen marine turtle populations respond positively to good conservation, like nesting beach protection and changes to fishing technology. But unless we change our reckless, throw-away attitude to plastic, we may well unwittingly undo all the marine turtle conservation success we have recently celebrated.

A University of Exeter survey has found turtles are being tangled up in lost fishing nets, plastic twine and nylon fishing line, as well as six pack rings from canned drinks, plastic packaging straps, plastic balloon string, kite string, plastic packaging and discarded anchor line and seismic cable. Turtles were also discovered entangled in discarded plastic chairs, wooden crates, weather balloons and boat mooring line.

Professor Brendan Godley, Professor of Conservation Science and Director of the Centre for Ecology and Conservation at the University of Exeter’s Penryn campus and the lead author of the new report warns that, as plastic pollution increases, more and more turtles are likely to become entangled.

84 per cent of the 106 experts surveyed - who rescue and rehabilitate stranded turtles in 43 countries - on the Atlantic, Pacific Caribbean, Mediterranean and Indian ocean coast, said they had found turtles tangled in rubbish, including plastic debris and lost or discarded fishing gear.

The report concluded that, based on the survey results, more than 1,000 turtles are likely to die due to entanglement, but Professor Godley suggests the numbers are likely to be far higher: “Plastic rubbish in the oceans, including lost or discarded fishing gear which is not biodegradable, is a major threat to marine turtles. We found, based on beach strandings, that more than 1,000 turtles are dying a year after becoming tangled up, but this is almost certainly a gross underestimate. Young turtles and hatchings are particularly vulnerable to entanglement.”

MCS Senior Pollution Policy Officer, Dr Sue Kinsey, says this shows the clear need for action on fishing gear: “At present the regulations regarding bringing waste into ports, including old and abandoned fishing gear, are under review. There’s a recommendation that all EU member states bring in a system whereby harbour fees cover 100% of the costs of delivering waste, including fishing waste, to ports and harbours by all vessels including fishing boats. We really hope that all states including the UK support this proposal which will help cut down on the amounts of fishing waste at sea, help to stop ghost fishing and ultimately protect wildlife.

The world-wide survey covering the major oceans where turtles live found that 91 per cent of the entangled turtles were found dead. They also suffered serious wounds from entanglement, leading to maiming, amputation or choking. Others that survived were forced to drag discarded rubbish or debris with them.

Published in Endangered Species Research, the report sheds light on the true threat of plastic pollution to marine turtles, which other research has shown, also eat plastic rubbish and marine creatures caught up in it.

Mortality from entanglement has increased substantially over the last century, as with marine mammals and birds.
Hatchlings and young sea turtles are particularly susceptible to getting tangled up in lost or discarded fishing gear or floating debris. Juvenile turtles ride on ocean currents to zones where floating rubbish and debris is concentrated creating an ‘ecological trap’. They also ‘set up home’ near floating debris and can remain there for years.

“We need to cut the level of plastic waste and purse biodegradable alternatives if we are to tackle this grave threat to turtles’ welfare,” concluded Professor Godley.

Olive Ridley turtles are the most likely species to get tangled up. The species nests in the hundreds of thousands. It forages in areas where marine debris can aggregate. It may also be attracted to feeding on marine rubbish, including discarded fishing tackle also known as ‘ghost gear’.

Since the 1950s, the fishing industry has replaced natural fibres such as cotton, jute and hemp with synthetic plastic materials such as nylon, polyethylene and polypropylene which doesn’t biodegrade in water.

MCS Head of Ocean Recovery, Dr Peter Richardson, says marine turtles have been around for more than 120 million years, survived the dinosaurs and catastrophic climate change but it’s human threats that turtles are simply not equipped to deal with.

“Plastic pollution in the ocean will get a whole lot worse before it gets better, posing another serious threat to turtles and other marine life. We have seen marine turtle populations respond positively to good conservation, like nesting beach protection and changes to fishing technology. But unless we change our reckless, throw-away attitude to plastic, and stop it flowing into the sea, we may well unwittingly undo all the marine turtle conservation success we have recently celebrated. That would be a shameful failing, so we must step up now and stop the plastic tide,” said Dr Peter Richardson.

On a positive note, the survey highlighted some communities are actively working to rescue turtles that get tangled up. Fishermen in Sicily volunteer to take part in the rescue of turtles in difficulty at sea and on beaches, and are trained to transfer them to rescue centres.